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Monday, May 30, 2011

I wanted a way to mount the monitor and be able to move it out of the way. What I decided to do is add drawer slides rated for 100lbs to the inside of the printer box on the slide is a hinged arm that the monitor and its electronics are mounted too. Its easiest to explain by showing pictures:

I also got the extruder up and going with my MK5 style nozzle with a .25mm orifice, the extruded ABS measured .30mm in diameter, the test was completed at 450 degrees F. If there is interest I may make a tutorial on how to make the nozzles or make a few and post them on eBay for sale. They are made of brass unlike the Makerbot stainless nozzles.

Sunday, May 29, 2011

A few days ago I received my timing belts for the Z axis and the 115 tooth belt was a perfect fit. After installing the belt I noticed that my alignment was off enough that the belt could come off the pulley, so I made a "flange." The flange, which you will see in a video posted below, also doubles as a Z axis adjustment knob.

As I did with the XY axis I added a substantial amount of weight to the z axis probably about 10 pounds to test the movement. In RepG it would jog at about 400 mm/min with out the axis being calibrated. It takes about a min for it to move through its 12ish inches of movement.

My new thermocouples came in, they are way to long but that was purposely done. The bed PID controller was bad, so I ordered a slightly better new one for the extruder and the old extruder one will be used on the bed.

I received some electronics from China that make it possible to use an old laptop monitor as a computer monitor using VGA or DVI.
Link: LCD Controller Board Kit with DVI Interface
It works flawlessly. I am now working on a over built monitor stand that includes drawer slides and cabinet hinges and the hinges from the laptop.

Tomorrow I plan on attaching the thermocouple to the hot end, calibrating the XYZ axis, and test the extruder to make sure that my nozzle works properly.

The video is of the printer playing the well known "Imperial March" gcode from the makerbot website.

After filming this video I decided to raise the Z axis and put a 10lb back of grout on top of the build axis to see if it seamed to loose steps or stop working. It remained working like that for the remainder of the 20min print. Afterwards I used rep z to do the maximum length jog at 4000mm/min and even with the excessive weight it preformed perfectly!

any other questions just ask.

I decided to measure the Z axis for the proper belt and I ordered 2 belts 115 and 119 tooth belts both 3mm pitch. Im hoping I can get the 115 tooth belt to work without a tensioner, if not I will use the 119 with a tensioner.

Right now I am hoping that the z axis will perform just as well as the XY axis. The z axis has always been the hardest part for me. I still need to work on some adjustments on it though.

Sunday, May 22, 2011

All of the electronics are now finished, 90% of wiring is completed, all wires are ran. Thermocouples are harder to extend than anticipated, so I ordered new ones at the proper length, 1 5m length and 1 3m length id rather them be longer than shorter.

The computer is up and going windows 7 ultimate 64 bit with all the needed software installed, RepG, Skeinforge, Python, Arduino, ect. Debating if I want to install Inventor on that computer as well. This printer is meant to be completely self contained, It will be possible to do everything from the printer: R&D, design, and manufacture.

Ran a 20 min dry run with the xy axis to see how well everything works, 1/8 micro stepping is 10X quieter than before with full steps, before I also had a bunch of rattles that has been fixed now.

Things left to do:
secondary belt splice for z axis
wire up thermocouples
solder up bed heater
retune/setup PID controllers
Add Z axis stop
Add/wire for fans on all stepper motors plus pin point fan for build surface
devise a monitor mounting solution that fits the printer well
mount keyboard and mouse in an adequate place
figure out why the left Y axis motor isnt working, wiring? driver? settings?
probably a few things I left off

The XY build platform has some flex to it, I believe it will be fine for printing, but im not satisfied with it. 90% of the flex is forward to backward due to the spacing of the two linear bearings, I plan to fix that in a future revision. But when looking at the parts that are flexing a lot of the flex is coming from my linear bearing rods. The rods are 1/2 diameter 22" long steel of some sort, they came with the bearings when I ordered them second hand. I may order 2 new linear bearing rods from Mcmaster to see if it helps with my problem.

I hope to be printing by the end of May or the first week of June, I really want to print a florescent green green lantern ring for the green lantern movie :P

Monday, May 16, 2011

The last post was an accumulation of a few months of work, today's post will be laid out in a better format.

At this point in time the mechanics of my printer are complete, I need to add another z axis belt, re tighten the z axis mounting bolts and the mechanics will be complete. I have finally added the print bed to the printer, and I have leveled it oriented to the print head so that no matter where the bed is located the distance between the print head and bed will vary less than .004" over the entire 12" bed. I am using stainless springs to assist in maintaining a level bed, only time will tell if this will be acceptable long term.

I have also completed the computer build for this printer it consists of the old parts from my old gaming computer in its entirety, except for its case. The case along with the case for the printer electronics follows the principle "function over form" which I learned long ago. The cases are made from wine crates, and have a 1/8" acrylic cover.

The printer electronics case houses gen4 Makerbot style electronics, a 400 watt power supply, a 350 watt computer power supply, solid state relays, 2 PID controllers, and switches for various parts of the printer. the 400 watt Lambda power supply is only for supplying 12v dc to various parts of the printer, at this point only the print head. It will be done away with once I convert to a cartridge based heater since it will operate off of mains voltage as the heated bed already does. The heatsinks are mounted to a strip of aluminum angle because I felt that the got to hot when I was operating the printer in the past.

The printer electronics box is going to have some aggressive cooling, 2 fans in the computer power supply, 1 fan in the Lambda supply, 4 120mm fans in the acrylic top, and I may add 2 more 80mm fans in the case somewhere.